The invention relates to a plastic frame for the mounting of an electronic heavy-current control unit, in particular for a motor vehicle. Such control units have a number of power semiconductor components and also a number of capacitors for smoothing the on-board voltages generated. These elements must on the one hand be supplied with operating voltages, and on the other hand the heavy current generated must be conducted away. Moreover, the heat generated must be dissipated, which requires a complicated cooler, often a water-cooled heat sink. All these elements must be arranged on a common carrier and be mounted in a vibration-resistant manner on account of the use in a motor vehicle.
To date, the individual elements such as power semi-conductor components, capacitors, busbars, heat sinks, etc. have been fixed by screws individually on a circuit board, which has required a high work outlay. Moreover, the elements have been potted with a vibration-damping sil gel, which has required a considerable amount of sil gel in the course of mounting on a circuit board.
The object of the invention, therefore, is to specify a measure which simplifies and reduces the costs of the mounting of an electronic heavy-current control unit, in particular for a motor vehicle.
The object is achieved by means of a plastic frame for the mounting of an electronic heavy-current control unit with cutouts for the positionally accurate receiving of busbars, metal plates and electrical/electronic components and also the potting compound thereof and with integrally formed snap-action elements for connection to a heat sink. An advantageous development is specified in the subclaims.
Accordingly, the plastic frame has cutouts for the positionally accurate receiving of busbars, metal plates and electrical/electronic components and also the potting compound thereof and integrally formed snap-action elements for connection to a heat sink. The plastic frame thus serves for fixing the busbars and the power semiconductor components and enables simple, time-saving connection to a heat sink on account of the snap-action elements. The cutouts for receiving the power semiconductor components also function, in a particularly advantageous manner, as wells for receiving the vibration-damping sil gel which protects the bonding wire connections of the semiconductor components, so that only a significantly smaller amount thereof is required.
The entire arrangement is accommodated in a housing and can be mounted with a spring element against the housing for the purpose of further vibration damping. The spring element additionally presses the elements fixed by the plastic frame according to the invention against the heat sink, so that better cooling can be effected by reduction of the thermal contact resistance between heat sink and the thermally loaded elements. In a development according to the invention, the spring element may be a constituent part of the plastic frame.